A case of acinic cell tumor of accessory parotid gland associated with “crystalloid” is presented. The patient was a 69-year-old female who was aware of a small mass of right buccal mucosa for 12 years. She consulted our clinic complaining of repeated swelling of the right parotid region. Oral examination revealed a submucosal elastic hard nodule beneath the right papilla parotidea. The lesion exhibited scattered radiopacity on roentgenogram. Under the clinical diagnosis of infected sialolithiasis in Stensen's duct, curettage was performed intra-orally. After two weeks, the submucosal nodule remained unchanged, then the lesion was excised along with the papilla parotidea under local anesthesia. Stensen's duct involved with the capsulated spheroid tumor was sacrificed and the proximal stump of the duct was sutured to the buccal mucosa. The patient recovered well after surgery.
The excised tumor was 15 mm in diameter, and histologically composed of eosinophilic cuboidal cells organizing tubular or acinar structure with poor fibrous stroma. Capsular structure with thin fibrous connective tissue was evident. Characteristic “crystalloid”, which is occasionally found confined in the parotid gland and the origin of which is not known, as well as psammorna body were scattered throughout tumor, and some of the crystalloids had cores consisting of psammoma body. But, there was no sialolith in the specimen. Histopathological diagnosis was acinic cell tumor.
The origin of the tumor in tins case was speculated to be accessory parotid gland rather than buccal minor salivary gland upon consideration of findings such as the anatomical relationship between the tumor and Stensen's duct, and identified crystalloid in the tumor. This is the first case reporting the existence of crystalloid in acinic cell tumor.
